Power brake system



Dec. 28, 1937. E. A. RocKwr-:LL

POWER BRAKE SYSTEM Filed July 2l, 1935 4 Sheets-Sheet 1 N l y l I lzz/@fdaC/fwez,

. Dec. 2s,l 1937.v

rai A. RocKwhELL f roWER BRAKE SYSTEM 4 Sheets-Sheei 2 Filed July 21,v 1933 hoe/1W- Ida/afd djoohwell, @l @Mw-4&7

Dec. 2s, 1937. E A, RQCKWELL 2,103,641`

FOWER BRAKE SYSTEM Fiied July.- 21, 1933 4 Sheets-Sheet 5 -l'ggg ma ffzz/e'.-

Edward d @cha/6%,

Dec. 28, 1937. E. A. RocKwELl. r'owsa BRAKE SYSTEM Filed July 21, 195s 4 `She'ets-Sheel. 4

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Patented Dec. 28, 1937 PATENT OFI-"ICE` rowaa BRAKE sYs'reM Edward Y A. Rockwell,

meme assignments,

. "Corporation, a coi-por Chicago, Ill., assigner, by

to General Auto Parti ation of Delaware Application Julyfzi, 1933, semi No. sais-ss I y asciaims. (Crissuur This invention' relates to` improvements in power brake systems for motorvehicles particularly of the mechanical typein whichthe pedal pressure of the operator isarnpliiledl by power derived from the propellershaft 'of the vehicle 'tovdevelopa desired braking force for applying the standard wheel brakes of the vehicle.

Mechanical power brake systems of this general `type are now well known in the art and essentially. comprise a power amplifyingunit whichis initially brought into operation by frictionai coupling with the propeller shaft so that the input force derived from the brake-pedal is proportionately amplified and deliveredv as an output braking force. The control unit portion or the means through which the frictional coupling withy 'the propeller shaft is obtained and the actuator or force multiplying unit havegenerally been directly associated. In che system the control unit and force multiplying' unit have been posi tioned in an offset relation to the propeller shaft but coupled thereto by gearing in order that the speed of the driving member of the control unit may be geared down with respect to the propeller shaft. This is open to the objection that the gearreduction'is in operation during movement of the vehicle. l

It is an object of m y 'invention to disclose a power Ibrake system in which thecontrol unit, consisting of the driving and driven clutch members, is directly associated with' the propeller shaft while the force multiplying unit is offset with respect tothe propeller shaftand is coupled to the control unit by gearing or by 'a cable drive. the advantage that all ythe parts arexnormally stationaryk except the driving clutch member, which rotates at'the speed of the propeller shaft. The-constructionv has the further advantagethat -the Lilorce multiplying uniti-may be positioned yat any convenient point on ythe vehiclel chassis for transmitting its out- `put force to the-wheel .brake linkage.A

Itis further-an object of my invention to disclose improvements in .the designv and construcf--tion' of the controlunit andyinv the design and construction of the Aforce multiplying .unit particularly to` obtain smooth and efficient action `through lubrication-and by the use of anti-friction bearings. v

Further and additional objects and advantages of my improvements willbe more readily apparent from the following description taken in connectionwlth the attached drawings, in which- `Figure l `is an elevation of the power brake FigureZ in Figure 1: .1 p 1 Figure 3 is a section on the plane indicated 3-4 in Figure 2; Y

Figure 4 is anend elevation;

vis a section on the piane indicated 2.-.2

Figure 5 is an end elevation 'of a mcdifiedc'onstruction; v Figure 6 is a section on the inmgure5: .i `Figure 7 is a cross section cfa further modification of the control unit; i I

Figure 8 isv a'partial plan view showing the installation of the constructions shown in Figures 5 and 6 ina vehicle chassis and in association with the brakelinkagand l I Figure 9 is Va side elevation of Figure 8.

In the embodiment disclosed in Figures .1 to 4, inclusive, the propeller shaft I8 extends rearwardly from the transmission casing. partially shown'at I2. 'Ihe shaft I2 is supported by bear- 'ing I3 in the casing I2. The usual speedometer gear is indicated I4. A drive sleeve I8 'is keyed to the shaft I8 and secured thereto by the nut I8. 'I'hedrive'sieeve i8 at its outer end is flanged as plane ,indicated at 20 to constitute part of the `usual universal joint. A friction ciutchdisk 22 is fastened to the flange 28 ofthe sleeve I8 by the bolts 24. The casing i2'has a flanged rib 28 and a tubular portion 28, which partially encloses the drive sleeve I6. 4

A power unit casing 88 is mounted on the tubular portion 28 of casing I2 and is suitably fastened to the flange 28 by bolts'82. The casing I8 has a main portion 24 surrounding the clutch disk 22 and an offset portion which forms a housing for an amplifying unit, as will be later described. The offset portion 38 has fastened thereto a cap 38 held by bolts 40. A shield 42 may also be secured by bolts 48 to the casing 88 to overlap the peripheral edge of the friction disk 22 and to form a substantially'enclosed structure. i

A sleeve 44 is rotatably mounted on the tubular portion 28 of casing I2. The sleeve 44 has an inwardly flanged outer end 4B to which is-fastened by suitable rivets Thedisk 58 includes a gear 52 and a fabric friction ring 64 which faces towards the clutch disk 22. The disk 50 is normally/stationary but may -be brought into frictional engagement with the disk 22 which is driven from the propeller shaft, whereupon the disk 50 will be frictionally rotated. The clutch disk 50 may be resilient in construction, as shown, lto modulatethe gripping action.

A pair of' supports 58' are secured within the casing 30 and carry pins 58 for pivotal support of a yoke 80. The-arms of the yoke 68 carry rollers 62 which are adapted to be forced against the forward side Aof the gear 52. 'An operating member 64 extends into the casing and is pivotally attached by pin 86 to a clevis 88 fastened to the yoke 60. .i s n I y It will be apparent through actuation of thatsymoving the rod u the usual brake pedal, the

disk 58 will be brought into rotation by contactingy The rotation` of thel with the rotating disk 22.

48 a control clutch disk Eli.

gear 52 is transmitted by suitable actuating means to operate'the rockable brake shafts 10 which are mounted in a bracket 12 integral with the cap 38. The shafts 10 have fixed 'thereto a pair of lever arms 14. The outer ends of lever arms 14 are connected by a thrust receiving roller 16 held in position by bolts 18. The roller 16 is engaged by an axially displaceable outputactuator extending outwards through a bearing 82 in the casing cap 38.

The casing 36 has a cylindrical portion 84 forming an internal bearing support for a rotatable sleeve 86 integral with a gear 88 meshing with the gear 52. 'I'he sleeve 86 and gear 52 are held in normal position by a. spring` element connected by pin 92 to the gear 88 and connected at its ends 94 to the casing 36.

'Ihe sleeve 86 in gear 88 has internal axial keyways 96 and the actuator 80 is xed to rotate with the gear 88 by a pin 98 engaging the keyways 96 which, however, permits axial displacement of the actuator 80 with respect to the gear.

Fixedly positioned within the cylindrical portion 84 of the casing is a centrally disposed support |00 held against rotation with respect to the casing 84 by a pin |02. The outer end of the support |00 which extends towards the actuator 80 is provided with exterior splines |04. The splines |04 constitute a mounting Vfor a `nonrotatable but axially displaceable sleeve |06 formed with an exterior spiral thread. A second sleeve 08 is internally spiralled and coupled to the sleeve |06. The sleeve |08 is splined to the keyways 96 of the outer sleeve 86 for rotation therewith. The rear or outer ends of the sleeves |06 and |08 engage a movable thrust abutment ||0 which in turn bears against the inner end of the output actuator 80. The forward or inner ends of theV sleeves |06 and |08 engage an antifriction thrust bearing i|2 which is mounted on the support |00.

'I'he spiral sleeves |06 and |08 and the bearing for the sleeve 86 should be well lubricated. I

show an oil seal unit 4 positioned in the casing 36 and engaging the outer portion of the drive sleeve 86 to retain the lubricant in the bearing therefor and the output actuator 80 and gear 88 have fastened therebetween a flexible boot ||6. The lubricant is therefore retained between the Yoil seal ||4 and the boot H6.

In operation the operator, by movement of the rod 64, will cause pivotal movement of the yoke 60 and axial displacement of the disk 50 to bring the fabric friction ring 64 into engagement with the friction surface of the rotatable disk 22. 'I'he rotation of the gear 52 will produce a partial rotation of the offset gear 88 and corresponding rotation of the outer spiral sleeve |08. Since the spiral sleeve |06 is held against rotation through its connection with the support |00, it will be apparent that one of the sleeves |06 or 08, dependent upon the direction of rotation, will be axially displaced in a rearward and outward direction to move the abutment ||0 and transmit an axial displacement to the actuator shaft 80. The amplified force of the outward thrust of the actuator 80 will produce application of the wheel brakes of the vehicle through rocking of the brake shaft 10.

In the m'odiiled constructions of Figures 5 and 6 the actuator unit is coupled to the control unit by a cable |20r instead of being geared thereto as in'the' first-embodiment described. The control unit is similar in most respects to the control unit previously described except that it is not enclosed in a casing. The propeller shaft |22 extends rearwardly from the transmission casing |24, which has mounted therein a sleeve |26. The drive sleeve |28 is splined to the propeller shaft |22 and held in position by a nut |30. The sleeve |28 has bolted thereto the friction disk |32. The disk |32 is positioned within the drum-shaped member |34 which has riveted thereto a friction disk |36 provided with a suitable annular fabric lining. The drum |34 is mounted by a flanged sleeve |38 upon the sleeve |26. `A support |40 fastened by bolt |42 to the transmission casing constitutes a mounting for a pivoted yoke-shaped input lever |44, the arms of which are in operative engagement with the drum |34 and the flanged sleeve |38. Operation of the lever |44 will serve to move the drum |34 axially to bring the fabric lining of the disk |36 into frictional engagement with the disk |32.

The actuator unit |48 may be mounted by a bracket |50 upon the chassis frame and includes an axially displaceable output member |52. 'I'he inner end of the output member |52 has mounted therein a ball bearing |54 to transmit the thrust from the abutment |56 which in turn is guided by the pin |58 sliding within the rotatable driving member |60. An externally spiralled inner sleeve |62 is splined to the driving member |60. An internally spiralled outer sleeve |64 is held against rotation by the engagement of rollers |66 with the at faces |68 on the opposite sides of the sleeve. 'I'he rollers |66 are mounted on pins |10 flxedly positioned in the casing |48.

'I'he driving member |60 is attached to the input drum |12 by rivets |14. The cable |20 is connected at |16 to the control drum |34 and at |18 to the actuator drum |12. The drum |12 is held in normal position by a spring |80. The end |82 ofthe nut |60 is supported by roller bearings |84 and at its end face engages a thrust bearing |86. A suitable oil seal |88 is provided contacting the member |60 and an additional oil seal |90 is positioned at the outer end of the casing engaging the slidable actuator |52. The actuator |52 may have fixed thereto a cap |82 as a further protection again'st leakage of lubricant. Y

It will be appreciated that with the propeller shaft rotating the disk |32 of the control unit will be driven at the speed of the propeller shaft but the drum |34 and all parts of the actuator unit will be normally stationary. The operator through suitable linkage may move the input lever |44 to frictionally couple the drum |34 with the disk |32 whereupon through the cable |20 the shaft |80 of the actuator unit will be rotated from its normal position. This relative rotation of the inner spiral sleeve |62 with respect to the outer spiral sleeve |64 will cause an axial displacement of one of the sleeves in a direction to move the output member |52 and tovapply the wheel brakes through suitable connecting linkage.

In Figure 'l a further modification of the control unit is disclosed. In this form the friction clutch members run in lubricant in a casing which is in communication with the transmission casing. The propeller shaft 200 rearwardly extends from the transmission casing 202. The control unit casing 204 is suitably secured to the casing 202. 'I'he shaft 200 is rotatably supported by a ball bearing unit 206 mounted in the casing 202 and at its rear end the shaft 200 has keyed and bolted thereto a universal joint connection sleeve 208. The casing 204 has an annular portion 2|0 constituting a bearing for the rotatable support of the hub 2|2 of friction disk 2|4. An

vamanti vble arm. levers 3|2 and 822 are provided at the output drum 2|6'is secured to the hub 2 I2 by bolts i 2|8. VMounted inthe outer'end of the drum 2|6 is an oil seal unit 220 bearing against the foonnection sleeve 208 to prevent the loss of lubricant from -the casing. 'An additional friction disk 222 is provided corresponding to but oppositely disposed with respect tothe friction disk 2|4. 'I'he disks 2|4 and`222 are connectedzfor -rotation as a unit'by bolts 224 which permit relative 'axial movement between the'disks. SThe disks are normally heldlapartiby springs 226 includes oppositely facing fabric "friction rings 234 `is attached to` the hubby rivets 236. `A thrust'collar 2 38 is mountedon the shaft'200 and abuts againstthe forwardend o f the connection "sleeve zos. The friction disk m is formediwith a radial flange 240which` is adapted to engage theA thrust collarr 238 when the control unit is brought into operation;

The friction disk 222 is formed with a' drumshaped hub portion 242 forming a racewayrfor rollers 244 carriedby the arms of the-inputyoke 246. The yoke 246 is .pivotally supported at 248 upon arbracket 250 secured by bolts 252 to the transmission case 202.` The lowerV end ofthe yoke 246 carriesa pin 25`4Ifitting in a slottedopening 256 formed in the 'slidable input member "258. 'I'he member 258 is supported at its rear end by a bearing portion 260 of casing 204 and extends through a bearing opening I262 formed Ain the transmission' case 202. An oil seal 264'is provided to` seal the bearing opening 262 against loss of lubricant from the casing. n `The outerend of the input member 258 is formed with a clev`is 266 to which suitable input linkage may be connected.

The operation of this control unit i s similar to those previously described in thatoperation `of the input will bring the rotatable and the'normally stationary 'friction clutch members into engagement-thereby producing a partial rotation of the output drum 2|6. This movement of the output drum may be transmitted by a cable as shown in Fig. 6 to a suitable actuator and arnplifying unit.y This design of i controlunit ,provides n howeverV an increased area of frictional contact and by having the friction members run in oil, the heat developed is rapidly dissipated.

Figures 84 and 9 illustratethe assembly of the vpower unit and the amplifier unit with the brake linkage of the chassis, kThe brake. pedal 300 is connected by link 302to the input lever Vv| 44 of the power unit which is mounted on the transmission case |24. 'Ihe transmission case is' rigidly secured to the engine frame 304 which, in turn, is usually carried by rollers mounted upon the frame. Since the amplifier unit |48 is rigidly'secured to the chassis frame |2|, there-must necessarily be some provision `for relative movement between the power unit and the amplifier unit. The use of the flexiblecable |20 between the output 4of the power unit andthe input of the amplifier unit takes care/of the relative movement that must occur. 'I'he units are therefore flexibly coupled. The output thrustfrom the amplifier unit` |48 is transmitted tolever arm'l306 fixedto the rock shaft ri108 which is supported at its end by brackets 3|0 f'lxed to the chassis frame.` vvDou- "ends of they rock shaft 308 through which lare lconnected the cables 8| 4 for actuating the front brakesand the cables SIB for actuating the rear n.

brakes. `An `emergency lever' 3|8 is also shown connected by'link 320 to the lever arm 822 secured to ,one end of the vrockA shaft "308.

1 ciaim: y

1."Pow'er brake operating mechanism for motor vehicles' including a control unit concentrically positioned with respecttothe propeller shaft 'of `the vehicle andactuator means offset withv respect to the propellershaft, 4saidcontrol 'unit comprising a clutch' element fixed to and rotatable with the propellerfshaft, a second normally stationary clutch element concentrically positioned with 'respect to .the first-mentioned clutch element, input meansl for bringing said clutch elements into engagement, saidotfset actuator means `comprising a driving member coupled to saidsecond clutch element and rotatable in either direction dependent k,upon the direction of`rotation of thepropeller shaft, a reciprocable output member and means for transmitting brake actuating movement to said output member inthe same directionfrom'said `driving lmemberregardless of the direction of rotation thereof.`

2. Powerbrake mechanism for motor vehicles comprising a control unit concentrically' positioned with respect to the propeller shaft of the vehicle, actuator' means voilset with respect to said power shaft, said vcontrol unit comprising a pair *of clutch elements, one of which is fixed with respect tosaidpropeller shaft to constitute .a driving member and the other clutch element s being a normally stationary driven member, in-

put means 'for bringing' said Aclutch members intojv engagement, said offset actuator means comprising a" normallyr stationary driving member coupled to the driven member of the control unit, a slidable output membe means for transmitting an output thrust to said output member in lthe same direction regardless of theL direction of rotation of .saidk driving member, a casing for said actuatorlmeans and lubricant sealingr means for said casing. i 3. Power brake mechanism for motor vehicles comprising a control unit concentricallyv positioned with respect to the propeller shaft of the vehicle normally stationary actuator means oisetfrom the propellershaft of the vehicle but adapted to derive rotation therefrom vupon actuation of said control unit, comprising, a casing, aninput `driving member rotatably kmounted in said casing, a slidableoutput member, a pair of relatively displaceable spirally coupled sleeves,

, oneof said sleeves being keyed for rotation with said driving member andthe other of said sleeves being retained against rotation with ,respect to said casing,iabutme nt means preventing 'displacement of said sleeves in one direction and a movable thrust abutment for transmitting relativeone of said sleeves being keyed for rotation with said driving member and the other of said sleeves being retained against rotation with respect to said casing, abutment means preventing displacement of said sleeves in one direction, a movable thrust abutment; for transmitting relative axial displacement of said sleeves to said output member in the other direction and means for retaining lubricant in said casing for lubrication of said sleeves. 4

. 5. Power brake mechanism for motor vehicles comprising a control unit concentrically positioned with respect to the propeller shaft of the vehicle normally stationary actuator means offset from 'the propeller shaft of the vehicle but adapted to derive rotation therefrom, comprising, a casing, an input driving member rotatably mounted in said casing, a slidable output member, a pair 'of relatively displaceable spirally coupled sleeves, one of said sleeves being keyed for rotation with said driving member and the other of said sleeves being retained against rotation with respect to said casing, abutment means preventing displacement of said sleeves in one direction, a movable thrust abutment for-transmitting relative axial displacement of said sleeves to said output member in the other direction and resilient means for normally retaining said input driving member in a definite position with respect to said casing.

6. Power brake mechanism for motor vehicles including normally stationary actuator means offset from the propeller shaft of the vehicle but adapted to derive rotation therefrom comprising, a casing, an input driving member rotatably mounted in said casing, a slidable output member, a pair of relatively displaceable spirally coupled sleeves, one of said sleeves being keyed for rotation with said driving member and the other of said sleeves being retained against rotation with respect to said casing, abutment means preventing displacement of said sleeves in one direction, a movable thrust abutment for transmitting relative axial displacement of said sleeves to said output member inthe otherdlreotion, said sleeves being disposed within said driving member and lubricant sealing means between said casing and said driving member, and a ilexible-boot connecting said output member and said driving member.

7. Power brake mechanism for motor vehicles lincluding normally stationary actuator means offset from the propeller shaft of the vehicle but adapted to derive rotation therefrom, kcomprising, a casing, an input driving member rotatably mounted in said casing, a slidable output member, a pair of relatively displaceable spirally coupled sleeves, one of said sleeves being keyed for rotation with said driving member and the other of said sleeves being retained against rotation with respect to said casing, abutment means preventing displacement of said sleeves in one direction and a movable thrust abutment for transmitting relative axial displacement of said sleeves to said output member in the other direction, the means for retaining one of said sleeves against rotation with respect to said casing comprising rollers mounted in said casing and'engaging opposite flat sides of said sleeve.

8. Power brake mechanism for motor vehicles including a control unit conoentrically positioned with respect to the propeller shaft of the vehicle comprising a control unit casing, a pair of clutch elements within said casing, one of said clutch elements being normally coupled for rotation with said propeller shaft, an output drum on the exterior of said casing fixed for rotation with the other of said clutch elements, input means extending into said casing for forcing said clutch elements into frictional engagement and lubricant sealing/ means for retaining lubricant within saidcetuiin'g-l whereby said clutch elements operate within'the`'iubricant of said casing.

9. Power brake operating mechanism for motory vehicles including a control unit concentrically positioned with respect to the propeller shaft of the vehicle and comprising a pair of clutch elements, one of which is fixed to' said propeller shaft, an output drum fixed for rotation with the other of said clutch elements, input means for forcing said clutch elements into engagement, brake actuator means comprising a casing fixed to thechassis frame of the vehicle, an input drum, av cable connecting the output drum of the control unit to the input drum of the actuator unit, a slidable output member concentrically positioned with respect to the input drum ofthe actuator unit and means including a pair of spirally coupled sleeves for converting the rotation of said input drum into slidable movement of the output memberl in the same direction regardless of the direction of rotation of the propeller shaft.

l10. A force multiplying unit for use in power brake systems comprising a casing, an input member rotatably mounted in said casing, apair of spirally coupled sleeves, means holding the inner sleeve against rotation with respect to said input member but permitting axial displacement thereof, roller means mounted in said casing engaging the outer sleeve to hold said outer sleeve against rotation with respect to said casing but permitting axial displacement thereof and a slidable output member mounted in said casing and protruding outwardly thereof, said output member being moved in an operative direction by the axial displacement of either of said sleeves from the normal position thereof caused by rotation of the input member. l

11. A force multiplying unit for use in power brake systems comprising a casing, an input member rotatably mounted in said casing, resilient means in said casing acting between said casing and said input member to hold said input member in a normal position with respect to said casing, a pair of spirally coupled sleeves, means holding the linner sleeve against rotation with resp'ect to said input member but permitting axial displacement thereof, means holding the outer sleeve against rotation with respect to said casing but permitting axial displacement thereof and a slidable output member mounted in said casing moved by axial displacement of either of said sleeves from normal position thereof.

12. A force multiplying unit for use in a power brake system comprising a casing, an input member rotatably mounted in said casing, a pair of spirally coupled sleeves in said casing,- means holding the inner sleeve against rotation with respect to said input member, but permitting axial displacement thereof, roller means mounted in said casing for holding the outer sleeve against rotation with respect to said casing but permitting axial displacement thereof, an output member slidably mounted in said casing and protruding therefrom, a thrust bearing in said casing engaging the inner end of said input member and a thrust bearing adjacent the outer end of said input member through which an axial disf members provided aioaeci placement .-of either'of said sleeves is transmitted to said output member.'

18. A\force multiplying unit for use in power Abrake systemsI comprising a casing, an input gear member Vhavingan integral sleeve vrotatably mounted in said casing, a pair of spirally coupled to said casing but permitting axial displacement slidably mounted in thereof, an output member said casing and protruding therefrom, the inner end of said output member being supported within the sleeve of said gear member, a thrust abutment bearing for the inner ends of -said spirally coupled sleeves and a thrust member' between the outer ends of said sleeves and said output'member whereby rotation of said gear member produnes an axial sleevesfto actuatesaid output member.

14. In a power brake system, a power unit, an input means associated with said power unit for bringing said power unit into action, output means for transmitting movement from said power unit, an amplifier unit adapted to be oscillated by and independently mounted with respect to said power unit, said amplifier unit having an input and anout'put coupled for relative rotary oscillation and means pller unit. c i

l5. In a power brake system for motor vehicles, a chassis, a 'transmission casing associated with said chassis, a power brake unit carried by said transmission casing, operator controlled input means 'for said power unit, an amplifier unit rigidly mounted on said chassis frame, a flexible coupling for transmitting by oscillation the output movement of said power unit to the input of said amplifier unit, said amplier unit having output means coupled for relative rotary oscillation kwith the amplifier input for transmitting` braise actuating movement to the wheel brake linkage;

16. In a power brake system for motor vehicles,

a propeller shaft, a normally inactive p'ower unit, a clutch associated with said propeller shaft, a power amplier unit spaced from said clutch unit, an oscillatory clutch unit to said amplifier unit, inputmeans for bringing said clutch unit into action to derive movement from said'propeller shaft and output means for transmitting brake actuating movement from said amplifier unit by relative rotary oscillation.

l'l.u power amplifier having an input means and an output means relatively rotatable with regard to the input means for work performing movement and a rotatably movable retracting spring for bringing one of said means back to its initial relative position with regard to the.l

other said means. o

18. A poweramplifier having aplurality of with cooperating mutually contacting inclined surfaces, one of which is rotatable relatively to the other, and a roller adapted to take the force of the reaction of one of said members.

' 19.' In combination, a pedal, a friction member adapted to be controlled thereby, an actuator comprising a plurality of members with inclined surfaces adapted to be brought into action by the friction member to produce longitudinal opposing rollers having a unitary support ada 4displacement of one of said for flexibly coupling the-y output of the power unit to the input of the amflexible cable connecting saidl and Pted to support one of said inclined surface members to decrease the friction produced by said longitudinal movement.

20. In a power source, a propeller shaft, a power amplifier having input and output means, the output means and a part of the input means bemovement of one of the actuator members.

ing positively and slidably coupled together forl rotative work performing movement, the power source being provided with a rotative friction means, the input means including a friction member normally stationary, concentric with the propeller shaft, and being adapted to be ,moved4 longitudinally into and out of engagement for its rotative movement with the rotative friction means of said power source for the control and release thereof.

y. 21. In a power source. a propeller shaft, a power amplifier having input and output means, the output means and a part of the input means being positively and slidably coupled together for krotative workperforming movement, the power source being provided with a rotative friction means, and cooperating spiral surfaces, one of which is adapted to remain stationary and the other of which is adapted to advance and return' for the said work performing movement, the power source including a friction member normally stationary, concentric with the propeller shaft, and being adapted to bemoved longitudinally into and out of engagement with the rotative friction means of said power source for the control and release thereof.

22. A work amplifying device comprising an automotive vehicle propeller shaft, a friction member slidably splined on the shaft, an output driven member, an input member for controlling the driven member, the output member being adapted toy be coupled with the friction member by thrust engagement for work performing relatively oscillatory rotary movement, a plurality of members being coupled to the, output.- member, having relatively inclined cooperating surfaces in .which relatively oscillatoryrotary movement is produced. 23. A work amplifying device comprising an automotive vehicle propellerA shaft, a friction member coupled on the shaft, an output driven member, an input member for controlling the driven member, the output member being coupled to the input member for relative movement to and from the input member and adapted to be coupled with the friction member for work performing relatively oscillatory rotary movement, a plurality of members being coupled to the output member having relatively inclined cooperating surfaces in lwhich relatively oscillatory rotary movement is produced.

24. A work amplifying device comprising an automotive vehicle propeller shaft, a friction member coupled on the shaft, an output driven member, an input member for controlling the driven member, the output member being adapted to be coupled with the friction member for work performing relatively oscillatory rotary' movement a plurality of members being coupled to the output member, having relatively inclined cooperating surfaces in which relatively oscillatory rotary movement is produced, the shaft being rotatable with regard to the output member, and a thrust member.

EDWARD A. ROCKWELL.

bearing for receiving the output 

